Hepatitis B is an infection of the liver caused by a virus that's spread through blood and body fluids.
It often doesn't cause any obvious symptoms in adults and typically passes in a few months without treatment, but in children it often persists for years and may eventually cause serious liver damage.
Hepatitis B is less common in the UK than other parts of the world, but certain groups are at an increased risk. This includes people originally from high-risk countries, people who inject drugs, and people who have unprotected sex with multiple sexual partners.
A hepatitis B vaccine is available for people at high risk of the condition.
Symptoms of hepatitis B
Many people with hepatitis B won't experience any symptoms and may fight off the virus without realising they had it.
If symptoms do develop, they tend to occur 2 or 3 months after exposure to the hepatitis B virus.
Symptoms of hepatitis B include:
These symptoms will usually pass within one to three months (acute hepatitis B), although occasionally the infection can last for six months or more (chronic hepatitis B).
Read more about the symptoms of hepatitis B.
When to get medical advice
Hepatitis B can be serious, so you should get medical advice if:
- you think you may have been exposed to the hepatitis B virus – emergency treatment can help prevent infection if given within a few days of exposure
- you have symptoms associated with hepatitis B
- you're at a high risk of hepatitis B – high-risk groups include people born in a country where the infection is common, babies born to mothers infected with hepatitis B, and people who have ever injected drugs
You can go to your local GP surgery, drug service, genitourinary medicine (GUM) clinic or sexual health clinic for help and advice.
A blood test can be carried out to check if you have hepatitis B or have had it in the past. The hepatitis B vaccine may also be recommended to reduce your risk of infection.
Treatments for hepatitis B
Treatment for hepatitis B depends on how long you've been infected for:
- if you've been exposed to the virus in the last few days, emergency treatment can help stop you becoming infected
- if you've only had the infection for a few weeks or months (acute hepatitis B), you may only need treatment to relieve your symptoms while your body fights off the infection
- if you've had the infection for more than 6 months (chronic hepatitis B), you may be offered treatment with medicines that can keep the virus under control and reduce the risk of liver damage
Chronic hepatitis B often requires long-term or lifelong treatment and regular monitoring to check for any further liver problems.
Read more about treating hepatitis B.
How hepatitis B is spread
The hepatitis B virus is found in the blood and bodily fluids, such as semen and vaginal fluids, of an infected person.
It can be spread by:
- a mother to her newborn baby, particularly in countries where the infection is common
- within families (child to child) in countries where the infection is common
- injecting drugs and sharing needles and other drug equipment, such as spoons and filters
- having sex with an infected person without using a condom
- having a tattoo, body piercing, or medical or dental treatment in an unhygienic environment with unsterilised equipment
- sharing toothbrushes or razors contaminated with infected blood
Hepatitis B isn't spread by kissing, holding hands, hugging, coughing, sneezing, or sharing crockery and utensils.
Read more about the causes of hepatitis B.
Preventing hepatitis B
A vaccine that offers protection against hepatitis B is available for people at high risk of the infection.
- babies born to infected mothers
- close family and sexual partners of someone with hepatitis B
- people travelling to or from a part of the world where hepatitis B is widespread, such as sub-Saharan Africa, east and southeast Asia, and the Pacific Islands
- people who inject drugs or have a sexual partner who injects drugs
- people who change their sexual partner frequently
- men who have sex with men
The hepatitis B vaccine isn't given as part of the routine vaccination schedule and sometimes you may have to pay for it.
Read more about hepatitis B vaccination.
Outlook for hepatitis B
The vast majority of people infected with hepatitis B in adulthood are able to fight off the virus and fully recover within 1 to 3 months. Most will then be immune to the infection for life.
Babies and children with hepatitis B are more likely to develop a chronic infection. Chronic hepatitis B affects around:
- 90% of babies with hepatitis B
- 20% of older children with hepatitis B
- 5% of adults with hepatitis B
Although treatment can help, there's a risk that people with chronic hepatitis B could eventually develop life-threatening problems such as scarring of the liver (cirrhosis) or liver cancer.
Read more about complications of hepatitis B.